Apparatus for treating fabrics



May 31, 1955 F. B. MORRILL EI'AL APPARATUS FOR 'fnm'rmc FABRICS 3 Sheets-Sheet 1 Filed Feb. 12. 1952 I I l 1| INVENTORS FRANK ULIA ATTORNEY May 31, 1955 B. MORRILL ETAL APPARATUS FOR TREATING FABRICS 3 Sheets-Sheet 2 Filed Feb. 12. 1952 INVENTORS FRANK B. Mmzmu. JULIAN E. woggyoam BY J g Wall" M72710 ATTORNEY May 31, 1955 F. B. MORRILL ETAL 2,709,270

- APPARATUS FOR TREATING FABRICS Filed Feb. 12. 1952 5 Sheets-Shem 3 n wbLm "a u m u T) g V a m v K m S m 15R fl lm fi L u n l, I UT a wiznn r m u Q 1 m m m m 3 m nn r o I: n o m m m u n m m n INVENTORS FRANK s. oamu. B JULIAN E.WOODWORTH 05am $74, ATTORNEY United States Patent APPARATUS FOR TREATING FABRICS Frank B. Merrill, North Adams, and Julian E. Woodworth, Williamstown, Mass., assignors to James Hunter Machine Company, North Adams, Mass, at corporation of Massachusetts Application February 12, 1952, Serial No. 271,166

Claims. (Cl. 15-89) This invention relates to the treatment of textile fabrics and particularly to an improved apparatus for loosening or removing foreign matter from fabrics. While the invention can be used for many purposes in which a beating or vibrating action on the fabric is desired, it is useful to particular advantage for de-burring woolen fabrics. Accordingly, for illustrative purposes the invention will be described with reference to this use, without, however, intending that it be limited thereto.

t is common practice to run woolen fabric through an acid bath which acts to carbonize foreign matter in the fabric. The carbonizing process is essentially one of dehydrating the vegetable matter in woolen fabric by means of an acid, usually sulphuric acid. As the water is driven out of the fabric by evaporation in a dryer, the acid held in the fabric draws water from the burrs, thereby carbonizing them. It has always been a problem in the art to remove these burrs completely and economically.

According to the present invention, the burrs are loosened from the fabric by the action of a series of balls vibrating on the fabric. The process comprises confining the balls in a space where they are distributed over an area of considerable width, usually the width of the fabric to be treated, and inducing rapid vibrations of the balls on the fabric in the space. Preferably, the balls are made of hard metal and are arranged loosely in the confining space so that they are free to move independently of each other between opposed horizontal walls; and the balls are caused to bounce up and down on the fabric as it is drawn through the space against the lower horizontal wall. The bouncing of the balls may be effectedsimply by subjecting the walls of the confining space to vertical vibrations. In this way, the balls are made to rebound with considerable force from one horizontal wall to the other with a vibrating action on the fabric. Due to the rounded contours of the balls and their rapidly repeated striking of the fabric against the lower wall, the burrs and other foreign matter in the fabric are quickly loosened so that they will readily become detached from the fabric when it emerges from the confining space for the balls.

In the practice of the process, it is desirable to subject both sides of the fabric directly to the vibrating action of the balls. This may be done by inverting the fabric after it emerges from the first treatment and then passing it under another set of vibrating balls in a second confined space. Alternatively, the fabric may be re-passed under the first set of balls, but in an inverted position.

The apparatus of the inv ntion comprises a housing forming a treating chamber having inlet and outlet openings for the fabric, a set of balls in the chamber, a conveyor for feeding the fabric through the chamber along the bottom thereof below the balls, and means for vibrating the balls vertically on the fabric. Preferably, the chamber housing is mounted for vertical movements on a frame, andthe balls are vibrated in the chamber by rapid oscillation of the housing vertically while the ice fabric is fed continuously through the chamber. The amplitude of the vibrations of the balls, and the frequency and force with which they strike the fabric, may be varied according to the characteristics of the fabric to be treated and the foreign matter to be removed from the fabric.

In the preferred construction of the apparatus, the treating chamber containing the balls is formed by a housing comprising closely spaced upper and lower horizontal walls, and opposed vertical ball-retaining walls at the front and back forming horizontal inlet and outlet slits for the fabric. In one form of the apparatus, the balls are vibrated by oscillating the housing vertically on a frame. Preferably, the chamber housing is mounted on the frame between sets of springs so that'it floats on the springs, and it is oscillated vertically by shafts rotating in bearings rigidly connected to thehousing and having eccentric weights. The arrangement of the' weights on the shafts, and the directions of their rotations, are such that the lateral components of the forces exerted by the weights on the shafts are inbalance, whereby the shafts, the housing and the balls therein are confined to vertical oscillations. A second chamber housing is similarly mounted and oscillated on the frame which supports the first housing, and the fabric emerging from the first housing is inverted and fed through the second housing under the balls therein, so that both sides of the fabric are acted upon directly by vibrating balls. The vertical oscillations of the two ball housings are equal but opposite in direction, the first housing moving up while the second housing moves down, and vice versa. In this Way, the dynamic forces of the two oscillating housings, and their associated parts, are balanced so as to prevent vibration of the frame of the apparatus.

For a better understanding of the invention, reference may be had to the following description taken in conjunction with the accompanying drawings, in which:

Fig.'1 is a front view of a preferred form of the new apparatus, showing the system for vibrating the balls;

Fig. 2 is a sectional view on the line 22 of Fig. 1;

Fig. 3 is a plan view of the apparatus illustrated in Fig. 1, showing only the main structural elements;

Figs. 4 and 5 are elevation and plan views, respectively, of the end retaining plates for the balls;

Fig. 6 is an end view of part of the power section of the apparatus, and

Fig. 7 is a schematic view illustrating the operation of the vibrating system for the balls.

Referring now to Figs. 1, 2 and 3, the apparatus comprises two sections, namely, a fabric-treating section shown' generally at 10 and a power section indicated generally at 11. At each end of the fabric-treating section 10 is a vertical channel beam 12, and at the top of section 10 are two longitudinal I-beams 13. Each I-beam 13 has plates 14 welded to its ends. The I-beams 13 are fastened at their ends to the channels 12 by bolts 15 similar manner, two I-beams 17 at the bottom of section 10 have plates 18 welded to their ends and are secured to the web portions of the adjacent channels 12 by bolts 19 and nuts 20. The frame formed by these beams and channels may be anchored tothe floor by any suitable means, such as bolts passing through holes 21 in the flanges of'the lower I-beams. The frame is further stiffened at the top by angles 22 running in the width dimension of the device and welded to the inside web portions of the channels 12. The angles 22 are fastened to the I-beams 13 by means of machine bolts 23 passing through spacers 24 and the flanges of the I-beams. 1

About mid-way between the top and bottom .of sec-. tion 10 are two channels 25 extending lengthwise of this section. Each channel has a fiat plate 27 welded to each end of the channel, the plates 27 in turn being secured to the web portions of the adjacent vertical channels 12 by means of bolts 28 and nuts 29. The channels 25 divide the fabric treating section into two portions which contain upper and lower treating chambers, respectively.

The upper treating chamber, indicated at 34) (Fig. 2), is formed by a housing comprising upper and lower walls or plates 31 and 32 arranged in spaced relation, these plates having fiat horizontal surfaces and flanged edges 31:: and 32a, respectively. Upper and lower closure members 33 and 34 are secured to the flanged edges 31a and 32a at both the front and the back of chamber 39. The closure members are spaced to form slits 36 and 37 constituting, respectively, the fabric inlet and outlet for the upper treating chamber 39. Resilient material 38., which may be rubber, for example, is fixed to the flat horizontal portions of plates 31 and 32 so as to form linings for the upper and lower walls of chamber 30. The ends of chamber are closed by plates 39. Each end plate 39, as best seen in Figs. 4 and 5, has a cover 41 of resilient material, such as rubber. The cover portion 41 is dimensioned so as to fit into the rectangular space defined by the resilient material 38 on plates 31 and 32 and by the inner faces of the closure members 33 and 34. Across the ends of closure members 33 and 34, and along the ends of plates 31 and 32, spacer piatcs 42 (Fig. l) are welded. Each end plate 39 is secured to a pair of spacer plates 42 by means of bolts 42a, so that the resilient cover 41 extends between the spacer plates. The chamber plates 31 and 32, therefore, are rigidly inter-connected by the end plates 39.

The treating chamber 30 is elongated but relatively shallow, the bounding walls being the resilient material 38 affixed to the top and bottom plates 31 and 32, closure members 33 and 34 at the front and back, and end plates 39. Within this chamber are hardened steel balls 43. The lining of the lower plate 32, which supports these balls, is level with the bottom of the inlet and outlet siits 36 and 37.

At the lower portion of the fabric treating section it is a lower treating chamber 44 similar to the chamber 30, the elements forming the chamber 44 being identical to and having the same numerical designations as the elements forming the upper treating chamber 39. However, the fabric inlet 36 and outlet 37 of chamber 44 are at the back and front, respectively, of the section 10.

The plates 31 and 32 are supported by a spring system which allows them to vibrate or oscillate vertically, and which will now be described. At the lower portion of the fabric treating section 10 are blocks 46 spaced along each of the I-beams 17, on which they are secured by bolts 47. Hollow plugs 48 are welded to the blocks 46 and have helical external grooves 50 for receiving the lower end portions of coiled springs 51. The upper portions of the springs 51 are engaged in helical grooves 52 of similar hollow plugs 53, which are secured in pairs to transverse plates 55. The plugs 48 and 53 are screwed into the ends of springs 51 so as to provide strong connections with the plugs.

The lower plate 32 of chamber 44 has transverse members 56 welded to its lower surface, the members 56 being spaced above and parallel to the transverse plates 55. Pillow blocks 57 are secured in pairs on top of the plates and have bearings (not shown) for two parallel shafts 58 and 59, extending lengthwise of the section 10. The plates 55 are rigidly connected to the overlying plate 32 by threaded studs 60 screwed into the transverse members '56 and extending loosely through aligned holes in the bases of pillow blocks 57 and the transverse plates 55. The studs are adjustably secured to the plates 55 and their blocks 57 by nuts 61.

A longitudinal support 63 is secured by bolts 64 on the channels 25 between the upper and lower chambers 30 and 44. The support 63 is connected through coiled springs 51a to the upper plate 31 of the lower chamber 44, in the same manner that the lower I-beams 17 are connected through springs 51 to the lower plate 31 of chamber 44. The upper and lower plates 31 and 32 of the upper treating chamber 30 are connected in a similar manner through springs 51b and 51c to the I-beams 13 and the support 63, respectively. The elements of these connections in which the springs 51a, 51b and 51c are included have been given the same reference numerals as the corresponding elements of the connections previously described in which the springs 51 are included. The springs 51a, 51b and 510 are associated with rotatable shafts 58a-59a, 58b59b and 58c59c, respectively, in the same manner that the springs 51 are associated with shafts 58 and 59.

Collars 65 are spaced along each of the eight shafts 5858c and 59-59c, to which they are secured by pins 66. Each collar 65 has a radial arm 67 on which an eccentric weight 68 is threaded. By screwing the Weights 68 inward or outward ontheir arms 67, it is possible to adjust the moment arms of the weights relative to the centers of the shafts upon which they are mounted. The arms '67 on each shaft extend in the same direction from the shaft, so that they are parallel to each other.

Fabric conveying rollers 69, 69a, 69b and 690 are mounted near the inlet and outlet slits 36 and 37 of the two chambers 30 and 44. These rollers extend along the slits longitudinally of the section 10 at the front and back thereof. The rollers 69 have at each end a shaft provided with a reduced portion 70 arranged to rotate within a supporting member 70a. The members 79a are secured to the flanged edges of the vertical chan nels 12.

The eight shafts 58, 59, etc., are each connected hrough a flexible coupling 71 to a shaft 72 extending through the web portion of channel 12 adjacent the power section 11. The power section comprises two vertical channel beams 73 connected at the top and bottom to the adjacent channel 12 by longitudinal members 74. The intermediate portions of channels 73 are connected to the adjacent channel 12 by longitudinals 76. A pulley 77 is secured to a shaft 78 rotatably mounted in the power section 11. The pulley is adapted to be driven from an electric motor (not shown) to drive the shafts S8, 59, etc. The shaft 58 is driven directly from the pulley shaft 78 through a flexible coupling 80 and the shaft '72 and coupling 71 connected to shaft 58. A gear 81 on pulley shaft 78 meshes with a similar gear 81a on an adjacent shaft 79, which is connected to shaft 59 through a connection (not shown) similar to the connection 8ll7271 to shaft 58. Thus, shafts 58 and 59 are rotated in opposite directions, as indicated by the arrows in Fig. 2, Shaft 78 is connected to an overlying shaft 78a by pulleys 82 and a belt 83, the shaft 781 driving shaft 55a through its connection 8i)-7271. The shafts S8 and 58:: are thus driven in the same direction, as indicated in Fig. 2. The shaft 781: and an adjacent shaft 79a are connected by intermeshing gears 81b and 310. The shaft 79a drives shaft 59a through a connection (not shown) similar to the connections 8t}72--7 1, whereby the shafts 58a and 59a are driven in opposite directions.

The shaft 79a has a pulley 84 connected by a belt 85 to a pulley 84a on a shaft 86 in the upper portion of section 11. Shaft 86 corresponds to the lower pulley shaft '78 but is driven in the opposite direction by reason of its pulley connection with shaft 79a (59a). The shaft 53-:- is driven directly from shaft 36 through its connection 80-72-71; and the shafts 59c, 58b and 59b are driven from shaft 86 in the same manner as the corresponding shafts 59, 58a and 59a, respectively, are driven from shaft 78, but in opposite directions, as indicated by the arrows in Fig. 2. The gears and pulleys 81-810 and 82 may be housed between plates 88 on the channels 73, the shafts 78, 79, 78a, 79a being journaled in these plates. Also, the pulleys 84, 84a and belt 85 may be housed in a casing 89 secured to channels 73.

In the operation of the apparatus, the cloth C is fed from a supply source (not shown) to the first roller 69, under which it passes into inlet slit 36 of the lower chamber 44, along the bottom of this chamber under the balls 43 therein, and out the outlet slit 37. It then passes under the second roller 69a and upward to and over the third roller 6%, from which it passes into the inlet slit 36 of the upper chamber 30, along the bottom of this chamber under the balls 43 therein, and through the outlet slit 37. From the upper slit 37, the treated cloth passes under the fourth roller 69c and then upward and over a fifth roller 69d, from which it passes to a suitable take-up reel, folder or the like (shown). The rollers 6969d constitute a conveyor means for feeding the cloth continuously through the chambers 44 and 30, and inverting the cloth as it passes from chamber 44 to chamber 30. In this way, first one side of the cloth and then the other side is exposed to the balls 43 in the two treating chambers, the unexposed side of the cloth in each chamber being supported on the lining 38 of the bottom plate 32 as the cloth is drawn through the chamber. The movement of the cloth through the chambers may be effected by driving the rollers 69-69d from a power source (not shown) or by a set of nip rollers (not shown) which draw the cloth from the last roller 69d, or by a combination of these expedients.

In preparing the apparatus for operation, the leading end of the cloth may be passed initially through each chamber 44-39 manually by securing the cloth to the underside of a thin plate, pushing the plate through the chamber against its bottom surface by way of the slits 3637, so that the plate and cloth pass under the balls 43, and then detaching the cloth from the thin plate and withdrawing the plate after it emerges from slit 37. When the cloth is ready for automatic feeding, the driving of pulley 77 for the shafts 58, 59, etc. is started, and the continuous feeding of the cloth is commenced.

As the shafts S8, 59, etc. rotate, their eccentric weights 6% cause the shafts to undergo oscillatory movements. These movements are permitted by the flexible couplings 71-80 and by the springs 51-510, which support the shafts 58, 59, etc., and the associated parts forming the treating chambers 30 and 44. Thus, the oscillatory movements of the vibrating means or shafts are accompanied by alternate expansions and contractions of the supporting springs 51-510. However, the oscillations are confined substantially to vertical movements because of the directions in which the shafts rotate, as shown in Fig. 2, and because of the positioning of the eccentric weights 68 on the respective shafts and the interconnection of each set of four shafts (e. g., shafts 58, 59, 58a and 59a) through the rigid parts 57, 55, 60, 31, 32 and 39. This is illustrated diagrammatically in Fig. 7, showing the positions of the eccentric weights 68 on the respective shafts at a certain instant of their rotations. As there shown, the weights 68 on each shaft are opposed horizontally to the weights on the adjacent shaft at the same level. As the shafts rotate at a uniform angular speed in the directions indicated by the arrows, the horizontal components of the forces exerted by the eccentric weights on each shaft will always be equal and opposite to the horizontal components of the forces exerted by the weights on the adjacent shaft, and so the resultant of these horizontal components for all the shafts will always be zero. Consequently, no lateral oscillations of the shafts will occur.

On the other hand, the weights 68 on the four lower shafts 58, 59, 53a and 59a reach their uppermost positions concurrently and also reach their lowermost positions concurrently. Accordingly, the vertical components of the forces exerted by these weights are not maintained in balance, as in the case of the horizontal components, but cause resultant upward and downward thrusts which are exerted alternately. Therefore, the four lower shafts, together with the plates 31 and 32 of the lower chamber 44 to which they are rigidly connected, will undergo vertical oscillations or vibrations as a unit. The same is true of the four upper shafts 58b, 59b, 58c and 59c, and the plates 31 and 32 of the upper chamber 30 to which they are rigidly connected, except that they are moving upward while the lower shafts 53, 59, 58a and 59a are moving downward, and vice versa. This is so because each shaft in the upper group of four is rotating in a direction opposite to the corresponding shaft in the lower group of four. Thus, while each group of four shafts and its corresponding chamber 36 or 44 will be oscillated vertically relative to the frame of the apparatus, the vertical dynamic forces exerted by the two groups are always equal and opposed, so that the resultant dynamic force on the frame is zero.

Because of this balancing of the dynamic forces, both vertical and horizontal, exerted by the eccentric weights 68 during the rotation of the shafts, vibration of the stationary structure of the apparatus is prevented. This is important not only from the point of view of reducing the strength requirements of the stationary structure, but also from the aspect of reducing the noise incident to operation of the apparatus. The noise is further reduced by providing the chamber plates 31 and 32 with the resilient linings 38, which cushion the impacts of the balls 43 as they oscillate or vibrate freely in the treating chambers, as will now be described.

The vertical oscillations of the chamber plates 31 and 32 by the oscillating means or shafts 58, 59, etc., cause the steel balls 43 to vibrate up and down on the cloth C passing through the chambers 44 and 30. The amplitude of the vertical vibrations of the balls is limited by the spacing between the opposing plates 31 and 32, the balls rebounding with considerable force between the upper lining 38 of each chamber and the upper surface of cloth supported on the lower lining as the chambers are oscillated. The frequency of the vibrations of the balls is a function of the speed of rotation of the shafts 58, 59, etc. Preferably, they are rotated at high speed, for example, about 1750 R. P. M., so as to cause rapid vibrations of the balls. it will be observed that the magnitude of the vertical thrusts exerted by the two oscillating systems, at any given speed, may be varied by adjusting the eccentric weights 68 on their arms 67. Also, by adjusting the transverse plates 55 vertically on the threaded studs 60, the compression of the springs 5151c (between which the shafts and treating chambers float) may be regulated. This regulation may be used to control the amplitude of the oscillations of plates 31 and 32, and the force with which the balls 43 strike the cloth, and to obtain resonance of the vibrating systems.

As the vibrating balls 43 beat upon the surface of the cloth C, they loosen the burrs and other foreign matter embedded in the cloth. Preferably, the balls are of small diameter, such as /s", and are arranged in closely adjacent relation in each treating chamber so that they cover in profile a major part of the area of the bottom lining of the chamber, for example, The amplitude of the vertical vibrations of the balsa may be quite small, for example, A: to /2". Because of their rounded contours, and the force and high frequency with which they beat upon the cloth, the balls 43 are highly effective to loosen and break up the foreign matter in the cloth very rapidly, so that the cloth may be fed through the apparatus at high speed. By reason of the close spacing of the upper and lower linings 38 of the chambers, as shown, and the elimination of lateral oscillations of the systems, the balls 43 will tend to remain quite evenly distributed over the cloth as it moves through the chamhers.

The loosened burrs and other foreign matter are car- 7 ried out of each treating chamber 44, 240 by the cloth and then fall from the cloth into a receptacle (not shown).

While I have shown a preferred form of the apparatus for vibrating the balls on the cloth, it will be under stood that the vibration of the balls may be effected otherwise than as illustrated. For example, they may be vibrated electromagnetically instead of mechanically, and the electromagnetic action may be applied intermittently, either directly to the balls or indirectly by vibrating the walls which confine the balls.

I claim:

1. A fabric treating apparatus, comprising a housing forming a treating chamber having an inlet and an outlet for the fabric, a set of balls in the chamber, means for vibrating the balls vertically in the chamber, and a conveyor for feeding the fabric through the chamber below the balls, by way of said inlet and outlet, whereby the balls are vibrated on the fabric.

An apparatus according to claim 1, comprising also a frame on which the housing is oscillatable vertically, said vibrating means being connected to the housing and operable to vibrate the balls by oscilalting the housing on the frame.

3. An apparatus according to claim 1, in which said chamber has upper and lower walls of resilient cushioning material.

4. An apparatus according to claim 1, in which said chamber has upper and lower horizontal walls, said inlet and outlet being positioned for feeding of the fabric along the lower wall while supported thereon.

5. An apparatus according to claim 1, in which said chamber has upper and lower horizontal Walls, the chamher also having opposed vertical ball-retsining walls hav ing horizontal slits forming said inlet and outlet.

6. A fabric treating apparatus comprising a frame, a 1

pair of housings mounted for vertical oscillating movements on the frame, each housing forming a treating chamber having an inlet and outlet for the fabric, a set of balls in each chamber, a conveyor for feeding the fabric serially through the chambers below the balls, by way of the chamber inlets outlets, the conveyor being operable to invert the fabric passing from one chamber to the other, and means for vertically oscillating the housings synchronously but in opposed relation, whereby upward movement of one housing is accompanied by downward movement of the other housing, to vibrate the balls on the fabric.

7. An apparatus according to claim 6, comprising also springs supporting the housings on the frame.

8. An apparatus according to claim 6, comprising also housings and movable vertically therewith, a member for drivin the shafts, and eccentric weights on the shafts for oscillating the shafts and housings.

11. An apparatus according to claim 6, in which said oscillating means include shafts rotatably mounted on the housings and movable vertically therewith, a member for driving the shafts, eccentric weights on the shafts for oscillating the shafts and housings, and adjustable connections between the shafts and weights for varying the ccentricity of the weights.

12. An apparatus according to claim 6, in which said oscillating means include a pair of substantially parallel horizontal shafts rotatably mounted on each housing and movable vertically therewith, eccentric weights on the shafts for oscillating the shafts and housings, the Weights on one shaft of each pair being displaced approximately 180 relative to the weights on the other shaft of said pair,

when the weights are in horizontal planes through the,

shafts, and means for driving the shafts of each pair in opposite directions, whereby said oscillations are confined substantially to the vertical direction.

13. An apparatus according to claim 6, in which said oscillating means include a pair of substantially parallel horizontal shafts rotatably mounted on each housing and movable vertically therewith, eccentric weights on the shafts for oscillating the shafts and housings, the weights on one shaft of each pair being displaced approximately 180 relative to the weights on the other shaft of said pair, when the weights are in horizontal planes through the shafts, and the weights on each pair of shafts being displaced approximately 180" relative to the weights on the other pair, when the weights are in vertical planes through the shafts, and means for driving the shafts of each pair in opposite directions.

14. A fabric treating apparatus comprising a frame, a housing forming a treating chamber having an inlet and an outlet for the fabric, springs mounted on the frame and supporting the housing for vertical movements relative to the frame, means for oscillating the housing vertically on the springs, a set of balls in the housing, and a conveyor for feeding the fabric through the housing below the balls, by way of said inlet and outlet, whereby the balls are vibrated on the fabric.

15. A fabric treating apparatus according to claim 14, in which said oscillating means include a pair of substantially parallel horizontal shafts rotatably mounted on the housing and movable vertically therewith, eccentric weights on the shafts, and means for driving the shafts in opposite directions with the weights on each shaft displaced approximately 180 relative to the weights on the other shaft, when the weights are in horizontal planes through the shafts.

References Cited in the file of this patent UNITED STATES PATENTS 937,180 Ridd Oct. 19, 1909 1,591,851 Macadam et al July 6, 1926 1,984,701 Reynolds Dec. 18, 1934 2,107,607 Gobel Feb. 8, 1938 2,520,594 Costa Aug. 29, 1950 2,554,701 Hackett et al. May 29, 1951 2,579,814 Genest Dec. 25, 1951 2,591,083 Maier Apr. 1, 1952 2,633,588 Rand et a1 Apr. 7, 1953 FOREIGN PATENTS 887,922 France Aug. 23, 1943 

